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View Full Version : How to use a powermatic mortiser



Wade Lippman
07-11-2023, 4:21 PM
I got one and bought the premium chisel from Lee Valley.

I can't set the handle so that it brings the chisel all the way down. If I set the handle at 2 o'clock (looking at it from the side) it nearly reaches the bottom, but not quite. But even then I can barely get the handle to come around.

I made some mortises and it cuts will, but won't go to the bottom.

The instruction don't address this. It really isn't functional like this, and since the machine gets good reviews I must be doing something wrong, but I sure don't know what. Any suggestions? Thanks.

Kevin Jenness
07-11-2023, 5:01 PM
Model#? Post some pictures and maybe someone will have some useful advice. If it's a fixed bed unit maybe you need to build up the base, if it's adjustable raise the table. The machine head ought to have at least a 4" of travel but maybe this is an oddball.

Richard Verwoest
07-11-2023, 5:11 PM
possibly there is a riser block installed?

Richard

Edward Weber
07-11-2023, 5:12 PM
Just about every mortiser has a type of stopping mechanism for depth of cut.
Look on the left side of the column, usually a rod with stop knobs of some kind or another.

Wade Lippman
07-11-2023, 6:03 PM
This is the mortiser
https://powermatic.com/1791310
yes, there is a stop block, but I have it set all the way at the bottom.
It won't go down because the handle hits the base of the machine.
It has 5" of travel as I have it set up. It claims 5.8" of travel, and I am sure it would have if the handle didn't hit the base first.

If I rotate the handle attachment from 2 o'clock to 3:30 it will work, but I am not tall or strong enough to use it then. There has to be another solution.

John Kananis
07-11-2023, 6:09 PM
Wade, if the handle is hitting the base, your options are either screw the handle into a different position or try a smaller handle (with less leverage).

Personally, for through work, I would use a sacrificial material instead of drilling into the table. And doing so raises the work (perhaps enough?).

John Lanciani
07-11-2023, 6:12 PM
What are you trying to do that you need more than 5" of travel?

Kevin Jenness
07-11-2023, 6:13 PM
This is the mortiser
https://powermatic.com/1791310
yes, there is a stop block, but I have it set all the way at the bottom.
It won't go down because the handle hits the base of the machine.
It has 5" of travel as I have it set up. It claims 5.8" of travel, and I am sure it would have if the handle didn't hit the base first.

If I rotate the handle attachment from 2 o'clock to 3:30 it will work, but I am not tall or strong enough to use it then. There has to be another solution.

Most chisels are 3" or less in length, so that plus a fraction is the practical limit of travel needed. Can you set the handle to get that long a stroke? Do the ways need adjustment or lubrication?

A through mortise in material thicker than the chisel length requires cutting from both faces.

Keegan Shields
07-11-2023, 6:16 PM
Wade, the base of the handle (where it attaches to the mortiser) pulls out (away from the body) and can be reindexed in a higher or lower position.

That's how the mortiser is adjusted for the height of the work piece since the table can't be raised or lowered like a drill press.

Wade Lippman
07-11-2023, 6:43 PM
Wade, if the handle is hitting the base, your options are either screw the handle into a different position or try a smaller handle (with less leverage).

Personally, for through work, I would use a sacrificial material instead of drilling into the table. And doing so raises the work (perhaps enough?).

That makes sense; a sacrificial piece would also prevent tear out (which I assume is a problem). Thanks.

Kent A Bathurst
07-11-2023, 7:31 PM
Keegan is on it. It’s a giant version of those little plastic spring-loaded handles

Kent A Bathurst
07-11-2023, 7:39 PM
Edit - if you can’t pull the handle base far enough out to clear the internal blocks, you might need to loosen the center bolt a bit to gain room. This should be a one-time adjustment

Edward Weber
07-11-2023, 8:52 PM
ALWAYS use a backer board when through mortising